efi: Deduplicate efi_file_size() / _read() / _close()

There's one ARM, one x86_32 and one x86_64 version which can be folded
into a single shared version by masking their differences with the shiny
new efi_call_proto() macro.

No functional change intended.

Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/1485868902-20401-2-git-send-email-ard.biesheuvel@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

1 files changed, 63 insertions, 0 deletions

diff --git a/drivers/firmware/efi/libstub/efi-stub-helper.c b/drivers/firmware/efi/libstub/efi-stub-helper.c
index 757badc1debb..6ee9164251a9 100644
--- a/drivers/firmware/efi/libstub/efi-stub-helper.c
+++ b/drivers/firmware/efi/libstub/efi-stub-helper.c
@@ -338,6 +338,69 @@ void efi_free(efi_system_table_t *sys_table_arg, unsigned long size,
 	efi_call_early(free_pages, addr, nr_pages);
 }
 
+static efi_status_t efi_file_size(efi_system_table_t *sys_table_arg, void *__fh,
+				  efi_char16_t *filename_16, void **handle,
+				  u64 *file_sz)
+{
+	efi_file_handle_t *h, *fh = __fh;
+	efi_file_info_t *info;
+	efi_status_t status;
+	efi_guid_t info_guid = EFI_FILE_INFO_ID;
+	unsigned long info_sz;
+
+	status = efi_call_proto(efi_file_handle, open, fh, &h, filename_16,
+				EFI_FILE_MODE_READ, (u64)0);
+	if (status != EFI_SUCCESS) {
+		efi_printk(sys_table_arg, "Failed to open file: ");
+		efi_char16_printk(sys_table_arg, filename_16);
+		efi_printk(sys_table_arg, "\n");
+		return status;
+	}
+
+	*handle = h;
+
+	info_sz = 0;
+	status = efi_call_proto(efi_file_handle, get_info, h, &info_guid,
+				&info_sz, NULL);
+	if (status != EFI_BUFFER_TOO_SMALL) {
+		efi_printk(sys_table_arg, "Failed to get file info size\n");
+		return status;
+	}
+
+grow:
+	status = efi_call_early(allocate_pool, EFI_LOADER_DATA,
+				info_sz, (void **)&info);
+	if (status != EFI_SUCCESS) {
+		efi_printk(sys_table_arg, "Failed to alloc mem for file info\n");
+		return status;
+	}
+
+	status = efi_call_proto(efi_file_handle, get_info, h, &info_guid,
+				&info_sz, info);
+	if (status == EFI_BUFFER_TOO_SMALL) {
+		efi_call_early(free_pool, info);
+		goto grow;
+	}
+
+	*file_sz = info->file_size;
+	efi_call_early(free_pool, info);
+
+	if (status != EFI_SUCCESS)
+		efi_printk(sys_table_arg, "Failed to get initrd info\n");
+
+	return status;
+}
+
+static efi_status_t efi_file_read(void *handle, unsigned long *size, void *addr)
+{
+	return efi_call_proto(efi_file_handle, read, handle, size, addr);
+}
+
+static efi_status_t efi_file_close(void *handle)
+{
+	return efi_call_proto(efi_file_handle, close, handle);
+}
+
 /*
  * Parse the ASCII string 'cmdline' for EFI options, denoted by the efi=
  * option, e.g. efi=nochunk.